Antikythera Fragment #2 - Ancient Tool Technology - The Original Dividing Plate?

One thing not discussed but I think is important is the teeth per inch in these gears. It would be easy enough to have a fixed divider with the proper spacing to get the tooth per inch needed across multiple gears. Calculating the needed diameter of the gear from the tooth count and spacing would be simple enough and you have a fixed divider for then spacing the gears so very little trial and error as discussed in the video.

Michael Herman

Hello mate - yes there are many additional tooth counts to consider to complete the reconstruction, I will cover this in detail once the research is published. Re tooth geometry, I've covered this in one of the videos already, but I don't recall which one - Cheers :)

Clickspring

I'm in the process of making this using the tooth numbers on your rule. As I'm doing this I'm wondering if there are any other wheels with different tooth numbers? As teeth are essentially equilateral for the larger tooth numbers I'm using the tooth pitch as a basis for the tooth size - any comments on that Chris?

Francis Milsom

One disservice we give to our ancestors is the myth that we are all a lot smarter now because we have learned so much. The truth is intelligence is not dictated by knowledge alone but by reasoning and curiosity. There are smart people in every generation and always have been so I don't see a problem with your setting out board. In fact there have been evidence that the method was used in all sorts of circumstances from architecture to mosaics. The only real surprise that we should take away from such a sophisticated device is just how stupid we are to believe our forefathers were less intelligent or capable than we are. If anything with the erosion of proper teaching and so much knowledge being sucked up into an ethereal internet there is a good argument for saying we are getting dumber. People used to calculate long division and trigonometry in their heads, theses days it is all people can do to remember phone numbers or birthdays without electronic assistance. Don't second guess yourself. I think you are being as true as one can to the skill of ancient world fabricator.

veritanuda

Definitely a good topic for a TGT. I, for one, would love to learn more about your tools of the trade. This theme is often employed by Youtube creators, such as John Saunders, NYC CNC (he's how I found you), Tom Lipton (Ox Tools), John Grimsmo (Grimsmo Knives), Keith Fenner (Turn Wright Machine Works) and many others who MAKE things.

Sam Robertson

Certainly Sam - I have 2, a simple clockmakers riveting hammer for precise peening and riveting and what think is basically a chasing hammer for forming and flattening objects. It might be a good topic for a TGT!

Clickspring

Another first-rate video, Chris. Kudos! As a recently retired machine shop owner, I know how much time & skill are required to make precision parts, essentially by hand, so I watch your videos with keen interest. Also ... could you tell us about your hammer of choice? I assume it's a clock maker design. Is it factory or shop made? Some details would be appreciated. Thanks!

Sam Robertson

Thank you very much Nathan, I really appreciate your encouragement. I'm definitely learning a lot about this thing 'by doing'. In fact this week I may well have nutted out something reasonably important - more details in a future video :)

Clickspring

Thank you very much Mike! More on the way soon :)

Clickspring

This is incredibly impressive work. You're the greatest example of a hidden gem (thankfully no longer hidden to me!) I've ever come across. I don't know how you came to be as technically/mechanically proficient as you are, but you've shown several times over what true brilliance looks like. Cheers, and keep the phenomenal stuff coming =)

Love your videos. Your attention to detail is first class. Experimental Archeology really helps shed light on the past that fills in the gaps of the texts; should be a degree program at a university.

Nathan Davey

I completely agree Jace - there is still one heck of a detective story buried within this little machine :)

Clickspring

I thin that the fragments are more interesting that the mechanism itself. The mechanism is just as cool but in its own way

Jace Walton

Cheers Thomas!

Clickspring

Thanks Charles :)

Clickspring

yes it was good to see Gottfried :)

Clickspring

Awesome. Thanks!

Mark Doss

Fantastic work, great hypothesis visualization, perfect for the budding precision machinist. Can't wait for the next "Fragments". Truly amazing stuff that has real world application for the small shop machinist!

Thomas Moore

Amazing!

Charles Rioux

HI Chris, Hope you saw the Google Doodle today of the 115th anniversary of the discovery of the Antikythera Device.

Gottfried Schuss

I wish there was mate :)

Clickspring

Terrific to hear that Michael :)

Clickspring

Thank you very much Douglas :)

Clickspring

Yes - where is Circular Pattern when you need it!

Clickspring

Today (17th May) marks the 115th year of the Antikythera mechanisms discovery, any bonus video to mark the occasion ?

Craig Somerfield

Someday I hope to make videos about my project as wonderful as your's Chris. They're so pleasant to watch.

This is an early version of how SolidWorks works. Maybe V0.00001. Thanks!

Paul Devey

Ha ha! Cheers mate :)

Clickspring

You are a friggin genus.

Joseph

Awesome Jace, you're well and truly hooked now!

Clickspring

Cheers Ryan :)

Clickspring

Cheers Mike :)

Clickspring

You are the reason that I bought a lathe! now I just need a mill and get scoll saw up and running again....

Jace Walton

Your videos are just amazing, Chris. Watching you explore ways to just divide circles is fascinating and captivating.

Ryan Das

Thank you for all the time and thought you put into these projects. The insight you provide is amazing!

Mike Michelizzi

Yes certainly Gregor - The teeth of the main drive wheel B1 are accepted to sit outside the calculating train, and so serve the purpose of simply permitting convenient movement of that wheel, via the input crown wheel A1. In that sense any practical tooth number would have sufficed, and by practical I mean any tooth count that would provide a mechanically sound, robust tooth size. B1 has an approximate outside diameter of 132mm. 200 teeth gives a tooth module of approximately 0.66 - a very chunky and robust tooth, with apex tip to tip of 2.1mm. A very strong tooth, able to withstand the input torque very well. Although it must be said approaching the point of being too coarse from the perspective of fine mechanism control. 280 teeth gives a module of approximately 0.47 - a reasonably delicate tooth form, 1.49mm between tooth tips, but consistent with almost all other wheels found in the device, and so still a reasonable candidate. Perfect for very fine control of the mechanism, but perhaps approaching the size where deformation of the tooth could occur with exuberant input torque from the user. So assuming no change to the outside diameter of the wheel, any tooth count (and therefore module) in between this range of 200 to 280 would provide a tooth form that is suitable to perform the role of robustly generating movement of B1. Latest research has the actual number of teeth for B1 at either 223 or 224. However there is a very strong belief among the research team that the number is in fact 223. If this is the case, then the choice of 223 is remarkable. Because if we consider all options within the range of approximately 200 to 280 teeth as valid candidates, then there had to be a very good reason to choose that more difficult division candidate over the more obvious options immediately adjacent. ie Why not select 224? 222? 240? etc My proposition is that 223 was selected out of simple manufacturing convenience. And that the choice strongly indicates the existence of an ancient division method very different to the current theory. ie One that leverages existing counts to propagate them to multiple wheels. E3 is known to have 223 teeth, so that division number was already required to be present on the division tool. Knowing that any robust tooth would suffice for B1, the maker would have been able to directly observe that the count of 223, fits nicely into the range of convenient and robust tooth sizes for the role performed by B1. It would have been clear that there was no need to perform yet another large division, when a suitable candidate was already present on the tool. And so the otherwise surprising tooth count of 223 was selected for B1.

Clickspring

Could you give a short explanation as to the use of 223 teeth? And why other teeth counts are just as good?

Gregor Shapiro

So pleased to hear that Tom, will do :)

Clickspring

Thanks Greg :)

Clickspring

Interesting hypothesis, seems credible. Presented, as usual, with top notch skill. Today I was chatting with a friend and your videos came up. I described the feeling of seeing the notice for a new Clickspring video as akin to that I remember when a new episode of Speed Racer came on during Saturday morning cartoons. Keep 'em coming :-)

Tom Colson

Thank you very much Michael :) I completely agree with you regarding the advanced state of technology in antiquity - Its very tempting to assume that it was all very primitive, but I think to do so would seriously underestimate the ingenuity of a very capable culture. This machine is perhaps the very best proof, because its features carry such strong implications: An advanced lathe capacity with a decent swing and rigidity, accurate division, accurate micro drilling capability etc. Had the Mediterranean region not been in such a state of conflict at that time in history, my mind boggles at the thought of where we might be today...

Clickspring

Thanks very much Peter :)

Clickspring

Thank you Gordon! Regarding writing this up: Its certainly something I have considered, although there's not much time left over after making the videos! Cheers mate :)

Clickspring

Brilliant thinking outside the box to make that dividing wheel.

Greg Nixon

Brilliant, as always!

Peter Young

Yet another superb presentation, Chris and extremely educational as usual. I particularly like your take on the master dividing disk... you are correct in your thinking: of course the maker would have had one; it stands to reason. This guy didn't make just one of these things; oh no! He was producing them one after the other for the discerning (and rich) sea captains, trading and/or battling their ways around the Mediterranean and beyond. I am sure that he constantly improved the design as he went along. He would need such a dividing plate to allow him to mark out each toothed wheel quickly and accurately. The ancient Egyptians had lathes ( that is for sure); they were also capable of flattening a piece of granite to extremely fine tolerances, not far short of what we can achieve 3 millennia later. Since the Greeks are known to have been in ancient Egypt over 2,000 years ago, it stands to reason that the Greeks would have filled gaps in their technology by copying the Egyptians. Maybe the Greeks didn't use a wooden or a (very expensive) brass/bronze indexing plate but one made from expertly faced granite, which would have eliminated both the expense of a copper-based alloy and the instability of temperature- and humidity-sensitive wood. You should not only video this project, Chris but write it up as a peer-reviewed paper... this little beauty could earn you a PhD in Historical Horology. It would definitely receive my vote!

Gordon Burns

I don't think the flatness would be much of an issue, at least in wood. There have been things like block planes found in pompeii that still work like modern ones.

James Cromwell

I definitely believe that antiquity was far more advanced than we give credit. I love the thought, effort and final products from this project. Thank you for your time!

Michael Leady

Chris, doesn't the dividing plate assume a pretty darn flat piece of wood or bronze/brass? (Please don't take this as nitpicking or casting aspersions in any way...! Obviously MDF wasn't available then and any hardwood planed/scraped flat would surely expand and contract with the seasons.) Anyway, is there much known in the literature about casting and machining for flatness? And to what tolerances? (My knowledge of historical technology is woefully ignorant. My trade puts me in contact with gold leaf (and its manufacture over the years), early bookbinding and printing techniques and some blacksmithing methods. Otherwise, zilch historically.)

Wes Baker

Hey John, so pleased you're enjoying the vids :) Yes number punches for the rule, a little wonky here and there, but I have convinced myself that it adds to the charm! Cheers mate :)

Clickspring

I so agree Stefan - there is some really interesting tech suggested by the machine itself, for example that calendar ring groove - that's one seriously precise trepanning cut for the 2nd century BC!

Clickspring

I love how much care and effort you put into even making your jigs. Did you use letter/number punches to mark the numbers on the rule? If so did you do it by eye or is there yet another jig for doing that?

John Creasey

This is truely exciting, just thinking about possibilities the instrument maker had way back.

Stefan

Terrific to have you on board John, much appreciated :)

Clickspring

Thanks Julian :) Yes I'm definitely learning a lot from the actual "doing". I have some terrific Fragment video topics coming up that have been directly generated by the build process.

Clickspring

The video brought to mind the book "Dividing the Circle" by Allan Chapman, which looks at the history and importance of accurately dividing a circle for astronomical measurement. This book starts from 1500 though, not the ancient Greeks. It seems to me you have learnt more about how this was done by actually doing it, than that historical investigation. Also, your video is a delight to watch.

Julian Gall

Wow! I'm a new Patron, I'm so happy I decided to do it. You do such amazing work and make such great quality videos. It is a total joy watching you work! I am catching up on the patron only content and loving it!!!

Thanks Paul :) Yes its hard to imagine the genius that came up with this thing being happy with all that repeat work!

Clickspring

Great video Chris. It really makes you think. A skilled lazy man will try and find shortcuts to repeat work. It is almost silly to think someone would have done each gear the slow way with a high risk or error. Love the "Simple Straight Edge" that is actually I highly engineered and polished strip of brass with locating pin and spacer :)

Paul Busby

Cheers Kent :) Although if I've understood you correctly, that carries a few demanding implications of its own - an implied swing of approx 45 inches, and a sizeable chunk of stable wood for each tooth count. There is certainly very strong evidence of lathe/turning technology, more detail in a later episode.

Clickspring

They had lathes, right? Take length of tape, or a string, or anything flexible: then make marks every 1 inch (or whatever length is convenient), so that for e.g. 288 divisions you end up with a string 288 inches long and markings or knots every 1 inch Then put a disc of wood on your lathe, and gradually turn it down until its circumference matches the length of your string.

Kent Overstreet

Cheers Kjetil, thanks for sharing :)

Clickspring

Cheers Andrew :)

Clickspring

Its turning out to be the best part of the build for me too - there is so much in this machine to talk about :)

Clickspring

Thanks very much Scott :)

Clickspring

Thanks very much Jeff, more on the way :)

Clickspring

Thanks Will :)

Clickspring

Cheers Justin :)

Clickspring

Ha ha! Awesome to hear that mate!!

Clickspring

Thank you Nikolaos :)

Clickspring

I appreciate your encouragement mate, thank you :)

Clickspring

Definitely Tim :)

Clickspring

Ha ha! yes it was! Cheer mate :)

Clickspring

Genius. I am going to have to watch a few more times to get what you are doing there straight in my head.

Andrew Robb

Hello Chris, This is also a way to do it : <a href="https://www.youtube.com/watch?v=8Rg2DT7BOE0" rel="nofollow noopener" target="_blank">https://www.youtube.com/watch?v=8Rg2DT7BOE0</a> :)

I'm really loving these speculations and theories. Really hammers home the fact that some maker actually spent months, or years, crafting this mechanism. Looking forward to seeing the rest of the build!

Sondre Ninive Andersen

More great eye candy. I love that I'm learning how problems may have been resolved then and now. Chris, you are a maestro. Keep up the great work.

Scott Clausen

Your "simple straight edge" is about as nice as any tool I own. Amazing work! Looking forward to more "simple" tools ;-)

Jeff Swayze

Outstanding!

Anything to save a few Drachmas! Might I suggest for tooth work you fix your file and move the work against it?

Justin Odhner

Btw after midnight here but once the video dropped I had to watch it !!

Awesome video and commentary as always. Makes one really wonder whether technology has been overused and simpler solutions are no longer used or thought of because we became lazy. Thank you Chris. Keep up the good work! PS. I was laughing when I saw the polished edge. That is trademark Chris all right. Tools need to look nice :)

Brilliant. I'm sure this isn't the last of the important archaeology this build will produce.

Andrew Hoadley

That's a very nice way of doing it Chris. It kinda opens the box on questioning what their life and technology really was like.

Tim bennett

Really nice jig Chris. That's a lot of math and punch marks :)

Jess Neal

Thanks very much Tristan, more on the way soon :)

Clickspring

Loved this video, it makes logical sense to use this set up. Great content as usual! Really looking forward to the rest of the series.

Tristan Sobey